Huang He Plain Mixed Forests

Spreading across northeastern China, the Huang He Plain Mixed Forests ecoregion widens eastward as the floodplains that define it become broader towards the coast of the Yellow Sea. In its lower reaches, the Huang He (Yellow River) carries more than 60 tons of silt every second (annualized mean)—enough to occasionally fill the channel and displace the flow. 

Historically, the Yellow River shifted its course every few generations, distributing fertile soils across a wide swath of eastern China, wreaking havoc in the process. ⁠Today, with leveeing, the channel bed of the lower Yellow River is elevated 10 m above the surrounding plain. 

Warm, moist summers and favorable soils of the Huang He plain enabled temperate forests of broadleaved deciduous trees and evergreen conifers to thrive in Paleolithic times. However, this landscape has been farmed since the early Holocene, at least 8,000 years ago, and it has been densely populated for more than more than 2,000 years. Few traces of the potential mixed forest vegetation remain today. Species richness for wild plants and animals is generally low, due to homogeneous habitat, cold winter temperatures, and millennia of intensive human activity.

The potential natural vegetation of the Shandong peninsula includes forests of deciduous oak, elm, Chinese pistache, and Chinese red pine. During the Pleistocene Ice Ages, when sea levels dropped, the northeastern part of Shandong peninsula was connected to the Dalian peninsula of Manchuria. Consequently, Shandong forests today retain a Manchurian character, with Mongolian oak, hazel, and linden, although many of these stands are increasingly replaced by species introduced from elsewhere: Japanese red pine, Armandii pine, and larch.

To the north and west, the Huang He plain is encircled by the mountains and loess plateaus of central China; to the south, it merges with the floodplain of the lower Changjiang (Yangzi River), comprising the largest alluvial landscape in temperate East Asia. Wild landscapes are relatively more intact on the boulder clad mountain slopes that crop up throughout this ecoregion, including the rocky spine of the Shandong Peninsula and the outcrops of Tai Shan and Song Shan, two sacred mountains that are protected as UNESCO World Heritage Sites. 

The famous Taishan Mountain, peaking at 1,545 m at the Jade Emperor Peak, has 80% forest cover, with pine at the higher elevations, chestnut and other deciduous hardwoods on the lower slopes. Mountain areas further inland support mixed forest stands dominated by Chinese red pine and Platycladus cypress. A grove of Platycladus in Dengfeng County in the western part of this ecoregion includes some gnarled trees estimated to be 4,500 years old.

Small, fragmented populations of North China leopard survive in mountain enclaves in the western part of this ecoregion where they prey on hare and wild pigs. This leopard subspecies, endemic to China, appears to be in rapid decline with an estimated population of 200–300 individuals nationwide.⁠ The north China sika deer is extirpated from the plains region, although it survives in zoos and is farmed for its antlers. Reintroduction to the wild is precluded by a lack of suitable habitat. 

Where they have not been excessively disturbed, riverine habitats, natural flood basins and coastal bays provide stopovers for migratory birds. The Shandong Peninsula is a significant nesting area for sea birds like the white-tailed eagle and terrestrial species like great bustard. Weighing about 10 kg, male bustards are one of the heaviest flying animals. Rongcheng Nature Reserve, at the eastern tip of the Shandong peninsula serves as a staging ground for whooper swan and a winter habitat for scaly-sided merganser. 

Most of the habitat in this ecoregion is utilized to feed the growing human population of China. Existing forest reserves in hill areas, wetlands, and remnant coastal habitats could benefit from improved management of the region’s nature reserves. Taishan Mountain and the other sacred mountains would benefit from better tourism management and delineation of core and buffer zone areas.

Priority conservation actions for the next decade are to: 1) delineate and manage remnant wetlands; 2) promote conservation education, especially through community engagement; and 3) uplist the North China leopard as critically endangered and develop a conservation plan for this endemic subspecies.

Citations 

1. Carpenter, C. 2000. Huang He Plain mixed forests (Abstract Only). https://globalspecies.org/ecoregions/display/PA0424https://globalspecies.org/ecoregions/display/PA0424. Accessed April 2019.
2. Elvin, Mark. 2004. The Retreat of the Elephants: an Environmental History of China. Yale University Press, New Haven.
3. Laguardia, A., Kamler, J.F., Li, S., Zhang, C., Zhou, Z., Shi, K. 2017. The current distribution and status of leopards Panthera pardus in China. Oryx 51(1): 153-9.